<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>my css4</title>
    <style>
        .container {
            width: 1280px;
            margin: 0 auto;
        }
        .c1 {
            width: 1280px;
            height: 200px;
        }
        .left {
            float: left;
            width: 200px;
            height: 500px;
            background-color: #b0bec5;
        }
        .right {
            margin-left: 200px;
            /*float: right;*/
            width: 1080px;
            height: 500px;
            background-color: #afb42b;
        }
        ul {
            list-style-type: none;
            padding: 0;
            margin: 0;
        }
        li {
            float: left;
        }
        .clear {
            clear: both;
        }
        a {
            font-size: 20px;
            width: 256px;
            display: block;
            text-decoration: none;
            background-color: #BEBEBE;
            height: 50px;
            line-height: 50px;
            text-align: center;
            border-bottom: 2px solid #900B09;
            color: white;
        }
        a:hover {
            background-color: #900B09;
        }
    </style>
</head>
<body>
<div class="container">
    <div class="banner">
        <img class="c1" src="http://5b0988e595225.cdn.sohucs.com/images/20170819/921fc88bc16640239dc0f9db25edf56a.jpeg">
    </div>
    <div class="nav">
        <ul>
            <li><a href="#">LINUX</a></li>
            <li><a href="#">PYTHON</a></li>
            <li><a href="#">HTML</a></li>
            <li><a href="#">CSS</a></li>
            <li><a href="#">JAVASCRIPT</a></li>
        </ul>
    </div>
    <div class="clear"></div>
    <div class="main">
        <div class="left">
            left
        </div>
        <div class="right">
            right
        </div>
    </div>
</div>
</body>
</html>